By Gardiner Harris, The New York Times, November 6, 2012
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| Yamuna River, by New Delhi is an ideal breeding ground for mosquitoes |
NEW DELHI — An
epidemic of dengue fever in India is fostering a growing sense of alarm
even as government officials here have publicly refused to acknowledge the
scope of a problem that experts say is threatening hundreds of millions of
people, not just in India but around the world.
India has become the focal point for a mosquito-borne plague that is
sweeping the globe. Reported in just a handful of countries in the 1950s,
dengue (pronounced DEN-gay) is now endemic in half the world’s nations.
“The global dengue problem is far worse than most people know, and it
keeps getting worse,” said Dr. Raman Velayudhan, the World Health
Organization’s lead dengue coordinator.
The tropical disease, though life-threatening for a tiny fraction of
those infected, can be extremely painful. Growing numbers of Western tourists
are returning from warm-weather vacations with the disease, which has reached
the shores of the United States and Europe. Last month, health officials in
Miami announced a case of locally acquired dengue infection.
Here in India’s capital, where areas of standing water contribute to
the epidemic’s growth, hospitals are overrun and feverish patients are sharing
beds and languishing in hallways. At Kalawati Saran Hospital, a pediatric
facility, a large crowd of relatives lay on mats and blankets under the shade
of a huge banyan tree outside the hospital entrance recently.
Among them was Neelam, who said her two grandchildren were deathly ill
inside. Eight-year-old Sneha got the disease first, followed by Tanya, 7, she
said. The girls’ parents treated them at home but then Sneha’s temperature rose
to 104 degrees, a rash spread across her legs and shoulders, and her pain grew
unbearable.
“Sneha has been given five liters of blood,” said Neelam, who has one
name. “It is terrible.”
Officials say that 30,002 people in India had been sickened with
dengue fever through October, a 59 percent jump from the 18,860 recorded for
all of 2011. But the real number of Indians who get dengue fever annually is in
the millions, several experts said.
“I’d conservatively estimate that there are 37 million dengue
infections occurring every year in India, and maybe 227,500 hospitalizations,”
said Dr. Scott Halstead, a tropical disease expert focused on dengue research.
A senior Indian government health official, who agreed to speak about
the matter only on the condition of anonymity, acknowledged that official
figures represent a mere sliver of dengue’s actual toll. The government only
counts cases of dengue that come from public hospitals and that have been confirmed
by laboratories, the official said. Such a census, “which was deliberated at
the highest levels,” is a small subset that is nonetheless informative and
comparable from one year to the next, he said.
“There is no denying that the actual number of cases would be much,
much higher,” the official said. “Our interest has not been to arrive at an
exact figure.”
The problem with that policy, said Dr. Manish Kakkar, a specialist at
the Public Health Foundation of India, is that India’s “massive underreporting
of cases” has contributed to the disease’s spread. Experts from around the
world said that India’s failure to construct an adequate dengue surveillance
system has impeded awareness of the illness’s vast reach, discouraged efforts
to clean up the sources of the disease and slowed the search for a vaccine.
“When you look at the number of reported cases India has, it’s a
joke,” said Dr. Harold S. Margolis, chief of the dengue branch at the Centers
for Disease Control and Prevention in Atlanta.
Neighboring Sri Lanka, for instance, reported nearly three times as
many dengue cases as India through August, according to the World Health
Organization, even though India’s population is 60 times larger.
Part of India’s
problem is that some officials view reports of dengue infections as politically
damaging. In September, Mamata Banerjee, the chief minister of West Bengal,
dismissed reports of an increasing number of dengue-related deaths, saying
doctors were misdiagnosing. “So everyone is earning a bad name,” she said at a
news conference.
A central piece of evidence for those who contend that India suffers
hundreds of times more dengue cases than the government acknowledges is a
recent and as yet unpublished study of dengue infections in West
Bengal that found about the same presence of dengue as in Thailand, where
almost every child is infected by dengue at least once before adulthood.
“I would say that anybody over the age of 20 in India has been
infected with dengue,” said Dr. Timothy Endy, chief of infectious disease at
Upstate Medical University in Syracuse.
For those who arrive in India as adults, “you have a reasonable
expectation of getting dengue after a few months,” said Dr. Joseph M. Vinetz, a
professor at the University of California at San Diego. “If you stay for a
longer period, it’s a certainty.”
The reason that such an extensive epidemic can hide in plain sight is
that as many as 80 percent of dengue infections cause only mild symptoms of
fatigue, said Anthony S. Fauci, director of the National Institute of Allergy
and Infectious Diseases. For many, the disease is experienced as “maybe just a fever that someone shrugs off.”
But the remaining 20 percent may be affected by more serious flulike
symptoms, with high fever, vomiting, searing pain behind the eyes, skin
rash, and muscle and joint aches that can be so intense that the illness has
been dubbed “breakbone fever.”
The acute part of the illness generally passes within two weeks, but
symptoms of fatigue and depression can linger for months. In about 1 percent of
cases, dengue advances to a life-threatening cascade of immune responses known
as hemorrhagic or shock dengue.
This potentially mortal condition generally happens only after a
second dengue infection. There are four strains of the dengue virus, and
infection with a second strain can fool the immune system, allowing the virus
to replicate. When the body finally realizes its mistake, it floods the system
with so many immune attackers that they are poisonous. Such patients must be
provided intravenous fluids and round-the-clock care to avoid death.
Twenty years ago, just one of every 50 tourists who returned from the
tropics with fever was infected by dengue; now, it is one in six, said Dr.
Velayudhan, the W.H.O. official. The Portuguese archipelago of Madeira is in
the midst of an epidemic.
On Oct. 9, Puerto Rico’s Health Department declared a dengue epidemic
after at least six people died and nearly 5,000 people were sickened.
The great danger of having hundreds of millions of people in India
with undiagnosed and unacknowledged primary infections is that a sudden shift
in the circulating dengue strain could cause a widespread increase in
life-threatening illnesses.
“We have been fortunate so far,” said Dr. Kakkar of the Indian public
health group. “But if, God forbid, we come across that situation we probably
need far better health-care management and inpatient care facilities.”
Trucks spewing pesticides against mosquitoes are now a
regular presence in New Delhi neighborhoods, but rapid and disorderly
urbanization — a hallmark of India’s development — increases the risks of
dengue proliferation, so few believe the government here can do much to halt
its spread.
The best hope for relief is a vaccine, but a recent trial of the most
advanced vaccine candidate largely failed.
“I
think we’re looking at 10 to 12 years before we see an effective vaccine, and
that’s if we’re lucky,” Dr. Halstead said. “In the meantime, we’re in trouble.”
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